Kangaroos have three vaginas. The outside two are for sperm and lead to two uteruses. The middle one is for giving birth.

The urinary tract goes through the middle of the three vaginas, which may be why joeys are so small (40,000 times smaller than adult kangaroos) — there’s no room for a bigger birth canal with the urinary tract in the way.

To go with the two sperm-vaginas, male kangaroos often have two-pronged penises.

Because they have two uteruses plus a pouch, female kangaroos can be perpetually pregnant.

Annotated image by Ed Yong.

Also possibly important to marsupial sex lives: Kangaroos can unhinge their lower jaws.

Ed says that the most common response to the news of triplicate kangaroo vaginas has been “don’t tell the Republicans.”